Take-down square.



F. l. KlMBALL.

TAKE-DOWN SQUARE.

APPUCATION HLED JULY 21. m2.

Patented May 11, 1915.

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WITNESSES.

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TAKE DOWN'SQUARE.

APPLICATION FILED JULY 21, 1912.

1,139,189. 1311911161 May11,1915.

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WITNESSES: INVENTOR:

F WZMZ Z [@zafiflrfi41 THE NORRIS PETERS 60.. PHOTo-LITHQ. WASHINGTON D. C.

20 e located within the lines of the square and ATENT FRANK I. KIMBALL, OF WEST HAVEN, CONNECTICUT, ASSIGNOR TO SARGENT & COMPANY, OF NEIV HAVEN, CONNECTICUT, .A CORPORATION OF CONNECTICUT.

TAKE-DOWN SQUARE.

Specification of Letters Patent.

Patented May 11, 1915.

Application filed July 2'7, 1912. Serial No. 711,932.

To all whom it may concern:

Be it known that I, FRANK I. KIMBALL, a citizen of the United States, residing in West Haven, county of New Haven, State of Connecticut, have invented certain new and useful Improvements in Take-Down Squares, of which the following is a full, clear, and exact description.

My invention relates to separable or take down carpenters squares and particularly to the means for locking together the arms or branches of the square.

The object of the invention is to provide a simple, effective and easily operable device for locking a tongue or extension on one of the arms in a corresponding groove or mortise in the other arm.

More particularly, my object is to provide animproved and simplified form of rotary cam device for locking together the arms,

easily accessible at one of the faces thereof. The construction is such that a slight rotation of the cam device will force the parts of the joint very tightly and securely together so that the arms will not be shaken loose from each other in ordinary use. 7

To these and other ends, the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

' released position preparatory to the separation of the arms, Fig. 6 is a fragmentary face view of one of the arms, detached, Fig. 7 is a similar view of the other arm, Fig. 8 is a detail of the cam and washer, and Fig. 9 is a detail of the cam operating key.

Referring to the drawings, 10 indicates one of the arms of the square and 11 the other arm. The arm 10 may be the body and the arm 11 may be the tongue, but this conforms to the same and slides therein with a certain amount of friction until it reaches the assembled position shown in Fig. 1.

According to the present invention the tongue 14 is split longitudinally and a rotary locking cam is interposed between the arms or branches of the split portion in order to spread said arms or branches into In the emboditight contact with the walls of the groove 13. r

In the embodiment shown, the tongue 1a is split or cutalong a median line, in a plane perpendicular to the plane of the square, by a kerf 15, which may extend throughout about half the length of the tongue, although this is not essential. At the extremity of the tongue 14: the same is provided with a cam recess 16 in communication with the kerf 15. A cam 17 rotatable in the arm 11 is adapted to engage the walls of the recess 16 and to spread apart the portions 18 of the tongue at opposite sides of the kerf 15 in order to force the edges 19 of the tongue 14 '(Fig. 6) into tight contact with the side edges 20 of the groove 15, thereby effectively locking together the two arms of the device.

The cam 17 is mounted in the elbow portion of the arm 11 and extends through said elbow portion and through the tongue 14, having its opposite faces flush with the re spective faces of the square. A washer 21 (Figs. 2 and 8) serves to mount the cam 17 rotatably in the arm 11 at one face of the square, while at the opposite face the cam is provided with a lateral flange 22 flush with the adjacent portion of the arm 11 (Fig.7) and adapted to extend into a shallow rabbet 23 extending marginally around the cam recess 16. Hence the flange 22 of the cam overlies the tongue 14: to a slight extent although its outer face is flush with that of the tongue. Between the washer 21 and the flange 22 the cam 17 is provided with laterally projecting cam flanges 17 adapted to coact with the opposite curved side portions 17 and 17 of the recess 16. The recess 16 is also provided with a shoulder 17 coacting with one of the cam flanges 17 in order to form a stop for the cam, as hereinafter described.

The cam 17 is provided with a slot 23* extending through the same and adapted to be engaged by a key 24 (Fig. 9) in order to turn the cam on its axis. In case the key is not at hand the cam may also be operated by inserting a screw driver or other implement into the slot 23 Supposing the square to be in the assembled position of Fig. 1, if it is desired to separate the arms, the key 24 or other device is inserted in the slot 23 and the cam is thereby turned in the direction of the arrow (Fig. 4) until it reaches the position shown in Fig. 5. In this position, the cam flanges 17 are substantially out of contact with the cooperating side portions of the cam recess 16 and the tongue 14 may be readily pulled out of the groove 13, as will be understood. When it is desired to re-assemble the device, the tongue 14 is slid into the groove 13 and the cam 17 is then rotated from the position shown in Fig. 5 to that shown in Fig. 4. In this operation the cam flanges 17" will be brought into cooperation with the opposite edges of the recess 16 and will force apart to a considerable extent the branches 18 of the tongue, so that the tongue will be forcibly held in the groove by a considerable amount of friction. After the cam has been moved to the locking position it will remain so tightly wedged between the branches of the split tongue that the arms will not be shaken loose even if the square is subjected to rather violent usage.

In order to indicate to the carpenter the unlocking position of the cam, one of the cam flanges 17 is arranged to abut against the stop shoulder 17 of the cam recess when the cam is in the unlocking position, as shown in Fig. 5. Hence in detaching the arms of the square the cam device will al ways he brought to stop in the unlocking position. It is also preferable to have the slot 23 in line with the kerf 15 in the unlocking position although this is not essential.

By splitting the tongue 14 and interposing the cam between the arms or branches thus formed, I am enabled to obtain an especially effective frictional locking action and at the same time, the arrangement is very simple and the locking device may be easily operated.

I do not claim any particular form of sliding joint between the arms, as my looking means may be used in connection with the various forms of sliding or other joints.

It will also be obvious that modifications in many other respects may be resorted to without departing from the scope of the invention. For example, it is not material in some aspects of the invention that the rotary locking device be mounted to turn in both arms, as in some cases it may be mounted in and carried solely by the arm having the split tongue or its equivalent.

What I claim is:

1. In a separable square, the combination of an arm having an under-cut groove extending transversely thereof, a second arm having a tongue fitting said groove, said tongue provided with a longitudinal slit or kerf, and with a recess in communication with said slit or kerf, a rotary cam member permanently mounted in the arm having the groove, and having cam surfaces adapted to engage the side walls of said recess, and thereby spread apart the side portions of the tongue into tight engagement with the walls of the groove, substantially as described.

2. In a separable square, the combination of anarm having a transverse under-cut groove at one end thereof, a second arm having a tongue of reduced width adapted to fit said groove, said tongue being provided with a longitudinal slit or kerf, and with a recess in communication with said slit or kerf, and a rotary cam member journaled in the arm having the groove, and extending into said groove, said cam member adapted to enter said recess as the square is assembled, and provided at opposite sides with cam surfaces to engage the respective 100 side walls of said recess and thereby spread apart the side portions of the tongue into tight engagement with the walls of said groove, substantially as described.

3. In a separable square, the combination 105 of an arm having a transverse extension, said extension being provided with a longitudinal undercut groove, a second arm having a tongue fitting said groove, said tongue having a longitudinal slit or kerf and a re- 110 cess adjacent the free extremity thereof communicating with said slit or kerf, a rotatable cam device comprising a washer embedded flush with the outer surface of one of the two parts, a stem member having cam 115 surfaces on opposite sides thereof adapted to engage opposite walls of the said recess and a circular flange on the other end of said stem flush with the outer surface of the square part, said cam device adapted to be 120 rotated in the plane of the square about its axis to spread or wedge apart the side portions or branches of the tongue so that they tightly engage the walls of said groove, substantially as described.

4. In a separable square, the combination of an arm having a groove, a second arm having a tongue fitting within said groove, said tongue being provided with a longitudinal slit or kerf, and with a recess adjacent its free extremity, and in communicamovement of said rotary member; substantion With said slit or kerf, a rotary member tially as described.

mounted in one of said arms and adapted In Witness whereof, I have hereunto set to engage opposite Walls of said recess, and my hand on the 25th day of J uly 1912.

thereby spread or Wedge apart the side por- FRANK I. KIMBALL. tions or branches of the tongue so that they Witnesses:

tightly engage the Walls of said groove, and J OHN H. SHAW,

a projection on said tongue to limit the BERTHA RAY.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner 0t Patents, Washington, D. 0. 

